Tuberculosis No ideal classification scheme exists for cutaneous tuberculosis (TB), but the system listed here is logical and takes into account the mechanism of disease acquisition. Unfortunately, unlike in Hansen disease, these categories do not correlate perfectly to host immunity.…
Superficial and Deep Mycoses Fungal infections, including dermatophytes and candida, are the most common type of infection worldwide. Cutaneous infections are divided into superficial (those that affect mostly the skin) and deep (those that are typically more invasive) mycoses. In…
Bacterial infections in the skin often have distinct morphologic characteristics that should alert the clinician that a potentially treatable and reversible condition exists. These cutaneous signs may be an indication of a generalized systemic process or simply an isolated superficial…
Acne Vulgaris Clinical Features Acne vulgaris is a chronic inflammatory disease of the pilosebaceous follicles, characterized by comedones, papules, pustules, nodules, and often scars. The comedo is the primary lesion of acne. It may be seen as a flat or…
Lichen Planus Lichen planus (LP) is a common, pruritic, inflammatory disease of the skin, mucous membranes, and hair follicles. It occurs throughout the world, in all races. Cutaneous LP affects 0.3% of men and 0.1% of women. Oral LP affects…
Pityriasis Rosea Clinical Features Pityriasis rosea is a mild inflammatory exanthem characterized by salmon-colored thin papules and plaques that are at first discrete but may become confluent ( Fig. 11.1 ). The individual patches are oval or circinate and covered…
Seborrheic Dermatitis Clinical Features Seborrheic dermatitis is common, occurring in 2%–5% of the population. It is a chronic, superficial, inflammatory disease with a predilection for the scalp, eyebrows, eyelids, nasolabial creases, lips, ears ( Fig. 10.1 ), sternal area, axillae,…
Within the dermis is a fibrillar matrix, termed ground substance, composed of proteoglycans and glycosaminoglycans. These acid mucopolysaccharides, produced by fibroblasts, are highly hygroscopic, binding about 1000 times their own volume in water. They are critical in holding water in…
Lupus erythematosus (LE), dermatomyositis (DM), scleroderma, rheumatoid arthritis, Sjögren syndrome, eosinophilic fasciitis, relapsing polychondritis, and related disorders are classified as connective tissue diseases. Basic to all these is a complex array of autoimmune responses that target or affect collagen or…
Flushing Flushing presents with transient erythema, usually localized to the face, neck, and upper trunk, and a sensation of warmth. Flushing may be physiologic or pathologic; though normally benign, causes range from emotions to hormones to medications and malignancy. Menopausal…